Nakul Bansal is teaching live on Unacademy Plus
DIGESTION AND ABSORPTION By Nakul Bansal 2nd year MBBS student VMMC and SJH, New Delhi 84 AIR in NEET 2016
Nutrition -Definition -Types of nutrients -Steps in nutrition process Digestion -Definition -Types of digestion process -Human digestive system and
Nutrition and its steps: Nutrition: Nutrition is the sum total of the processes involved in the taking in and the utilization of food substances by which growth, repair and maintenance of the body are accomplished. Chemical substances present in food are called as nutrients. Types of nutrients- Macronutrients include carbohydrates, proteins, lipids (fats) and also alcohol. You consume them in great, that is "gram," amounts. They provide you with energy and building blocks for your body growth and repair. Also called as proximal principles of food. Micronutrients include vitamins and minerals. You usually consume them in small, that is "milligram," amounts. They, for example, help to build your bones, enable muscle contractions, transport oxygen via the blood; they have many other functions in your body. Also called as protective principles of food
Steps of holozoic nutrition Ingestion: The process of taking food inside the body is called ingestion. Digestion: In digestion the ingested food is converted into simple form with the help of digestive enzymes Absorption: In this stage the food digested in second step is absorbed into the cells of body. Assimilation: Assimilation is the process of utilizing the food absorbed in third step by various cells of the body Egestion: Egestion is the final step of holozoic nutrition in which the undigested food is removed from the body.
INGESTION Taking in food Breakdown of complex food substances to soluble food substances IDIGESTION Digested food diffuses into bloodstream ABSORPTION Transport and use of absorbed food by body cells ASSIMILATION EGESTION Removal of undigested food
Digestion: The process of conversion of complex and insoluble organic substances to simple absorbable forms is known as digestion. Various mechanic and biochemical events take part in digestion. It is a hydrolytic process and carried out by various enzymes. Types of digestion: ceil a) Intracellular: When the process of digestion occurs within the cell in the food vacuole. Examples: Protozoa, Porifera, Coelenterate and free living Platyhelminthes. b) Extracellular: When the process of digestion occurs outside the cel, Examples: Coelenterates and phylum Platyhelminthes to phylum Chordata tiving PlatyhelminthesPe: Protozoa, Porifera, Coelenterate
Human digestive system: Oral cavity Parotid gland Mouth -Pharynx Submaxillary and sublingual glands Oesophagus Liver Gall bladder Stomach Pancreas Duodenum Transverse colon Ascending colon leum Caecum Vermiform appendix Jejunum Descending colon Rectum Anus It consists of human digestive system(GIT) and associated glands.